Heat retention member for cylinder bore wall, internal combustion engine, and automobile

Abstract

A cylinder bore wall insulating member has a contact surface that comes in contact with a wall surface of a cylinder bore wall that forms a cylinder block of an internal combustion engine and defines a groove-like coolant passage. An internal combustion engine in which the cylinder bore wall has a uniform temperature may be obtained using the insulating member.

The invention claimed is: 
     
       1. A cylinder bore wall insulating member having an outer perimeter circumscribing an area within and having a contact surface that comes in contact with a wall surface of a cylinder bore wall that forms a cylinder block of an internal combustion engine and defines a groove-like coolant passage, and thereby covers the wall surface of the cylinder bore wall across the entirety of the area of the area of the cylinder wall insulating member,
 the contact surface being formed of an ethylene-propylene-diene rubber or a nitrile-butadiene rubber, 
 a reinforcing material being provided inside the insulating member or on a back surface of the insulating member opposite to the contact surface, and 
 the insulating member being pressed against and secured on the cylinder bore wall using a securing member that includes a wall contact section. 
 
     
     
       2. The cylinder bore wall insulating member according to  claim 1 , the insulating member being pressed against the cylinder bore wall due to a spring biasing force. 
     
     
       3. An internal combustion engine comprising a cylinder bore wall insulating member that has a contact surface that comes in contact with a wall surface of a cylinder bore wall that forms a cylinder block of the internal combustion engine and defines a groove-like coolant passage, the cylinder bore wall insulating member being disposed so that the contact surface comes in contact with the wall surface of the cylinder bore wall that defines the groove-like coolant passage,
 the contact surface being formed of an ethylene-propylene-diene rubber or a nitrile-butadiene rubber, 
 a reinforcing material being provided inside the insulating member or on a back surface of the insulating member opposite to the contact surface, and 
 the insulating member being pressed against and secured on the cylinder bore wall using a securing member that includes a wall contact section. 
 
     
     
       4. The internal combustion engine according to  claim 3 , wherein entirety of the cylinder bore wall in a circumferential direction is covered with the cylinder bore wall insulating member. 
     
     
       5. The internal combustion engine according to  claim 3 , wherein part of the cylinder bore wall in a circumferential direction is not covered with the cylinder bore wall insulating member. 
     
     
       6. The internal combustion engine according to  claim 3 , wherein an upper end of the cylinder bore wall insulating member in a vertical direction is positioned lower than a position that is lower than an upper end of the groove-like coolant passage by ⅓rd of a length from the upper end to a lower end of the groove-like coolant passage. 
     
     
       7. The internal combustion engine according to any one of  claim 3 - 5 , wherein the cylinder bore wall insulating member is pressed against the cylinder bore wall due to a spring biasing force. 
     
     
       8. An automobile comprising the internal combustion engine according to  claim 7 . 
     
     
       9. An automobile comprising the internal combustion engine according to any one of  claim 3 - 5 .